IT Steroids for SSNHL: Does Schedule of Injections Impact Outcome?

Introduction: Both systemic steroids and intratympanic steroid injections (ITI) are commonly used as treatments for sudden sensorineural hearing loss (SSNHL). While systemic steroids have been shown to improve hearing recovery, some patients cannot tolerate systemic steroid therapy, and ITI must be utilized as the sole primary treatment. While many providers utilize an injection schedule of one injection per week, this schedule has not been demonstrated to be superior to one in which injections are performed at shorter intervals. The objective of this study is to determine whether hearing recovery is impacted by the duration of time elapsed between injections when ITI are used as primary treatment for SSNHL.

Methods: A retrospective review was performed evaluating all patients at a tertiary care center undergoing at least three IT injections in 2021for treatment of SSNHL. Patients treated with systemic steroids before IT steroid course were excluded from final analysis. Success of treatment was defined by hearing recovery meeting one of the following three criteria: improvement by 10dB in pure tone average (PTA) or speech recognition threshold (SRT) compared to pre-injection audiogram, or improvement in word recognition score (WRS) by 12%. Prognostic factors studied included time between IT injections, delay to treatment, concurrent treatment with PO steroid, associated presenting symptoms, and comorbid medical conditions.

Results: 54 patients were included for review. 36 patients received primary PO steroids and were excluded; 18 patients remained for analysis. Treatment schedules with less than 7 days between injections correlated significantly with audiometric improvement (p < 0.05). Use of concurrent steroids and treatment initiation within one week also demonstrated significance (p < 0.05). Presence of pre-injection tinnitus, vertigo, diabetes, or obesity were not significant prognostic factors.

Conclusions: For primary treatment of SSNHL with ITI, reducing time between treatments to less than 7 days may improve audiometric success compared with injections performed at longer intervals.